A wide area network (WAN) is a network which covers a large geographical area, and use communications circuits and systems to connect the network nodes. “Wide area” coverage is defined by a number of fixed base stations which are typically distributed geographically over a large area and are connected over a wired network. Often these stations are distributed in such a way that no one station could cover the same geographic area by itself (however this isn't always the reason for such a wide area network). This enables a first mobile wireless radio within coverage of a first fixed base station to communicate with other (second, third, etc.) mobile wireless radios within coverage of remote fixed (second, third, etc.) base stations. Other types of units which can be on the wide area network (WAN) are console units—these are units where users can communicate to other console users as well as mobile radio users; however the console connects to the network over a wire rather than wirelessly.
Wireless wide area networks utilize communication technologies such as WIMAX (Worldwide Interoperability for Microwave Access), UMTS (Universal Mobile Telecommunications Service), GPRS (General Packet Radio Service), CDMA (Code division multiple access), GSM (Global System for Mobile communications), CDPD (Cellular Digital Packet Data), HSDPA (High-Speed Downlink Packet Access), 3G (third generation), 4G (fourth generation), and the like, to transfer data.
Within a wide area network, a variety of communication scenarios can co-exist. For example, one use of the wide area network is to enable a group call (i.e. one mobile radio user transmitting to many mobile radio users who are listening). Other examples of communication scenarios within a wide area network are a private call (i.e. one mobile radio user to one other mobile radio user), a short data call (e.g. text messaging), and an emergency call.
Low-tier, cost conscious markets (for example school districts, mass transit, construction companies, etc.) cannot typically support the expense of higher initial startup costs or high recurring fees within a network that higher tier markets can afford (for example, law enforcement, federal agencies, etc.). Further, these lower tier markets are typically willing to experience a slightly diminished level of reliability in order to save cost.
A means of lowering the most impacting aspect of cost is reducing recurring fees. Most wide area systems today rely on low delay, low jitter, low packet drop, low outage rate, T1's. The T1 (or T-1) carrier is a commonly used digital transmission service. It consists of twenty four (24) separate channels using pulse code modulation (PCM) signals with time-division multiplexing (TDM).
Reducing recurring costs that are incurred by monthly T1 fees can lower overall network costs. T1 and fractional T1's are an order of magnitude more expensive than Internet connections. The Internet is a worldwide, publicly accessible series of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a “network of networks” that consists of millions of smaller domestic, academic, business, and government networks, which together carry various information and services.
However the Public Internet suffers from several important limitations: it is higher delay than T1's; Internet jitter suffers from a statistically different distribution than T1's; Public Internet suffers from packet drop (drop is negligible on a T1); and T1 outages are at least an order of magnitude less frequent than the Internet.
Accordingly, there is a need for a method and system for enabling low cost wide area network (WAN) communication.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.